Evelyn Underhill (6 December 1875 – 15 June 1941) was an English Anglo-Catholic writer and pacifist known for her numerous works on religion and spiritual practice, in particular Christian mysticism. Her best-known work is Mysticism, published in 1911.
All that is necessary for the triumph of evil is that good men do nothing.
The evil of the world is made possible by nothing but the sanction you give it.